The research proposed investigates adult age differences and similarities in the procesing of words, sentences, and nonlinguistic stimuli, with the long-term objective of increasing understanding of the memory and language difficulties that accompany aging. Three series of studies are outlined, all sharing the aim of differentiating those aspects of memory and language processing that change with aging from those that do not. The first two series of studies compare the aging of implicit memory (which does not require an introspective report of remembering) with that of explicit memory (which requires conscious recollection). Both series test the hypothesis (1) that in contrast to explicit memory, implicit memory remains relatively constant in the course of normal aging, and (2) that there are some age differences, nonetheless, in the acquisition of implicit associative memory, i.e., in the acquisition of new associations. The first series focuses on verbal associative memory with the aim of specifying the conditions under which there are differences in the occurrence and structure of implicit memory for associations among the nouns in a sentence. Implicit memory is inferred from priming of word-stem completions, and explicit memory is assessed by cued recall. The second series focuses on nonverbal associative memory with the aim of examining the rate of acquisition of memory for a sequence. Implicit memory is assessed by changes in response time to a repeating sequence, whereas explicit memory is tapped in a prediction task. The third series of studies analyzes word retrieval difficulties (tip-of-the- tongue experiences), with the aim of specifying the components of word retrieval that change with age and those that do not. The goals are to determine whether there are age differences (1) in the patterns of memory activation that follow and unsuccessful attempt to retrieve a word, and (2) in the degree to which people's judgments of their knowledge of the word are related to such activation. Memory activation will be inferred from priming in a word/nonword (lexical decision) judgment task.